Dynamic foam insulation/shading system with inflatable bags

ABSTRACT

A building insulation/shading system comprises a dynamic fluid foam generator and a plurality of deployable/retractable flexible containers mounted to the building structure. Each container has an inlet connected to the dynamic fluid foam generator and an outlet for draining the liquid resulting from the degradation of the insulation foam directed in the container by the foam generator. The containers are movable between an expanded operational position in which the flexible containers are filled with dynamic fluid insulation foam and a retracted storage position in which the flexible containers have been emptied and retracted along the sides of the building.

RELATED APPLICATION(S)

This application is a continuation of International Patent Application No. PCT/CA2004/001083 filed on Jul. 23, 2004, which claims benefit of U.S. Provisional Patent Application No. 60/489,116 filed on Jul. 23, 2003, which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a system and a method for periodically insulating and/or shading a building structure, such as a greenhouse, an atrium or any structure or part thereof having glass or plastic roofs, walls of fixed or flexible materials.

2. Description of the Prior Art

Building structures having cavities formed between double light transmitting roof or wall membranes for receiving degradable or replaceable foam insulation are known. The roof and wall cavities can be periodically filled with degradable foam to provide shading or thermal insulation. However, when it is desired to let the light pass through the building envelope in order to take advantage of the solar energy, the foam can be readily dissolved and removed from the cavities. Examples of such buildings can be found in U.S. Pat. No. 3,672,184 and No. 4,562,674. One problem with such buildings is the difficulty to fit the foam generating system into a roof structure without causing major changes to the roof of the building. Also, it impedes the light transmission or the ventilation through the roof. Indeed, to date, no system allows providing foam only to certain sections of the roof, while leaving other roof cavities empty. The roof surface has to be completely covered with the foam with no possibility of allowing light to pass through a given section of the roof. Furthermore, with the prior art foam insulation systems, it is not possible to open the roof for allowing natural ventilation. The roof has to be of a permanent nature. When the insulation system is not being used, the day light still has to pass through double skin membranes to penetrate the building envelope. This reduces the intensity of the light penetrating the building envelope.

SUMMARY OF THE INVENTION

It is therefore an aim of the present invention to provide a new replaceable insulation/shading foam system which includes a dynamic insulation foam container that can be retracted to a storage position when not being used.

It is also an aim of the present invention to simplify and increase the flexibility of installation of a dynamic liquid foam insulation/shading system in a building structure.

It is a further aim of the present invention to minimize the cost involved in the installation of a dynamic liquid foam insulation/shading system in a building structure.

Therefore, in accordance with the present invention, there is provided an insulation/shading system for a building structure, comprising a dynamic fluid foam generator, a plurality of inflatable/deflatable containers adapted to be mounted to the building structure, each of said plurality of containers having an inlet connected to said dynamic fluid foam generator for allowing filling of the flexible containers with a dynamic fluid insulation foam and an outlet for draining the liquid resulting from the degradation of the insulation foam, said containers being movable between an expanded operational position in which the containers are filled with said dynamic fluid insulation foam and a retracted storage position in which the dynamic fluid insulation foam has been substantially emptied from the containers.

In accordance with a further embodiment of the present invention, there is provided a method for periodically insulating/shading a building structure comprising the steps of: a) mounting a plurality of inflatable/deflatable bags to the building structure, b) generating a degradable fluid insulation foam, and c) deploying the bags from a retracted state to an expanded state and filling the bags with the degradable fluid foam.

In accordance with a still further general feature of the present invention, there is provided a system for periodically thermally shielding/shading a building structure with a degradable fluid foam for insulation and shading, the system comprising a foam generator adapted to produce the degradable fluid foam, a distribution pipe connected to an outlet of the foam generator for receiving the foam, and a number of sprinklers connected to the distribution pipe for spray-applying the foam on the building structure exterior or interior.

In accordance with a still further general aspect of the present invention, there is provided a system for periodically insulating/shading a transparent building structure, comprising a number of sprinklers spraying liquid foam onto a membrane adapted to be mounted to the building structure, and a foam return line for recuperating the liquid which result from the degradation of the foam over time.

Another feature of the present invention involves a containerization of the foam system that will be readily mounted to the building structure by using a series of expandable/retractable bags. The bags can be filled with liquid foam or vacuumed to a tight package when not in use. The use of extendable/retractable bags in a dynamic fluid foam insulation system allows reducing the whole attachment system to the existing structure with minimal modifications. It also provides for the full control of the application of the dynamic insulation system for new and existing structures. Finally, it permits the modularization of the system for multiple uses.

Another feature of the present invention is directed to a system for washing the exterior of a greenhouse, comprising a number of sprinklers distributed along a distribution line connected to a source of washing fluid, the sprinklers extending outwardly of the greenhouse for spray-applying a washing fluid on the exterior of the greenhouse.

In accordance with another general feature of the present invention, there is provided a method of periodically producing a sound insulation, comprising the steps of: providing a source of foaming solution consisting essentially of a surfactant and water, providing a source of pressurized air, and mixing the foaming solution with the pressurized air to generate dynamic liquid foam.

The present invention is further generally characterized by the combined use of a delivery system of the liquid foam using air pressure to enlarge the flexible containers (e.g. the inflatable/deflatable bags) and enhance the foam insulation quality and the use of a vacuum system to collapse the foam and reduce the flexible container to a tight small volume in order not to impede light transmission when the system is not being used.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which:

FIG. 1 is a perspective view of a greenhouse equipped with liquid foam filled deployable and retractable bags in accordance with a preferred embodiment of the present invention;

FIG. 2 is a front elevation view of the greenhouse illustrating the foam generator which feeds the deployable and retractable bags with high density fluid insulation foam, the bags being shown in a retracted position;

FIG. 3 is a front elevation view of the greenhouse illustrating the bags in a partially deployed position;

FIG. 4 is a front elevation view of the greenhouse illustrating the bags in a fully deployed position;

FIG. 5 is an enlarged front view of a portion of the greenhouse illustrating the details of the liquid foam supply and return circuits of one the bags;

FIG. 6 is a front elevation view of the greenhouse illustrating the wall and roof cavities of the greenhouse in the process of being filled up with liquid foam sprayed through a series of sprinklers connected to the foam distribution line of a mixing chamber in which a foaming solution is mixed with pressurized air in order to produce foam in accordance with a second embodiment of the present invention;

FIG. 7 is a front elevation view of the greenhouse illustrating the roof and wall cavities filled with the foam produced in the mixing chamber; and

FIG. 8 is a perspective view of the greenhouse shown with the wall and roof cavities thereof partly filled up with liquid foam sprayed by the sprinkler of the foam distribution line.

FIG. 9 is a front elevation view of the greenhouse with sprinklers extending out of the greenhouse roof structure to spray-apply a layer of foam on the outer surface of the structural membrane covering the greenhouse skeletal framework.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As will be seen hereinafter, the present invention is generally directed to a flexible or permanent insulation foam container system designed to provide for modular insulation of solar structures of many different types. The example shown in the Figures is applied to a hoop style greenhouse. However, it is understood that the present invention could also be installed in variable connected gutter systems as well as other types of greenhouses or building structures, such as residential, commercial or industrial buildings. The object is to provide a method and a system for effectively insulating roof or wall by sections or completely with containers, such as flexible bags, that are transparent or translucent or non transparent. This is accomplished by bringing dynamic fluid insulation foam to selected sections of the building structure so as to insulate or shade these sections.

Now referring to FIG. 1, there is shown a hoop style greenhouse 10 having a conventional skeletal framework 12 including among others a number of vertical supporting columns 14 and transversal horizontal trusses 16. Each pair of adjacent transversal trusses 16 defines a bay 18. In accordance with the present invention, inflatable/deflatable bags 20 are selectively deployable in the bays 18. In the illustrated embodiment, there is provided two series of bags 20, one on each side of the greenhouse 10 (see FIGS. 1 to 4). Each bay 18 thus contains two opposed facing bags 20 adapted to be deployed to bring the opposed facing distal ends thereof in contact with each other so as to completely close the bay 18. In FIG. 1, some of the bags 20 on the right side of the building 10 are deployed while all the bags 20 on the left side are retracted. The bags 20 are deployable in a transversal direction with respect to the greenhouse 10, i.e. in a direction parallel to horizontal trusses 16. Similar bags could also be provided between adjacent pairs of vertical columns 14 for deployment along a vertical direction.

Each bag 20 is supported by at least one cable 22 (FIG. 2) that stretches from one side of the structure to the other, thereby allowing the bag 20 to slide along the cable by eye rings 24 (FIG. 5) or other attachments. There may be more than one cable 22 per side of the bag 20. Each cable 22 may have attachment on either side of the bag 20, the center of the bag 20, and on top and bottom thereof. This would depend on the size of the bag 20 and the weight of the material. The bags 20 are generally 10 feet long by 5 feet wide but this may vary to as small as 1 foot width and, depending on the circumstances they may be anywhere from 4 inches deep to 15 inches deep or more, depending on the need, the location, the climatic conditions and other dictates of the location and the style of the structure.

As best shown in FIGS. 2 to 4, the greenhouse 10 has a double layer covering membrane 26 stretched over the skeletal framework 12. The covering membrane 26 can be made out of a polyethylene sheet or other materials such as polycarbonate, glass or other forms of plastic to form the skin of the greenhouse 10. An expansion bar 28 is provided at the top of the structure to maintain a minimum distance between the inner 26 a and the outer 26 b layers of the covering membrane 26. It is not necessary in this application that there be a double layer skin membrane to the building as the operation of the insulation foam bags 20 is totally independent of the actual roof system of the greenhouse 10. However, if such a double layer covering membrane is already in place on the framework 12 of the greenhouse 10, the liquid foam insulation system of the present invention can be easily installed to work within the existing structural design. It is noted that in some climatic regions, the bags 20 could also be arranged to combine together and form the roof system of the greenhouse 10 in place of the covering membrane 26.

As shown in FIGS. 2 to 4, each series of bags 20 is connected to a foam generator 30 generally comprising a surfactant reservoir 32, a pump 34, an air blower 36 and a mixing chamber 38. The reservoir 32 contains a foaming solution consisting essentially of a surfactant and water. The foaming solution can be provided in the form of a concentrated solution derived from a hydrolyzed protein concentrate base, such as used in the fire fighting foam art. The foaming solution is pumped into the mixing chamber 38 by the pump 34 via a supply line 40. While the foaming solution is being pumped in to the mixing chamber 38, the air blower 36 is operated to inject pressurized air into the mixing chamber 38 via an air injection line 42. The surfactant solution is injected at a pressure between 30 psi to 80 psi while the air is injected at pressures varying from about 10 psi to about 100 psi. As opposed to conventional foam generators where a soap solution is sprayed onto a screen by a fan at the entry of the wall and roof cavities, the above-described foam generator provides for the production of a high density liquid with very fine bubbles from a central location upstream of the bags 20. This provides better insulation properties and thus permits to reduce the size of the containers receiving the foam.

The liquid foam being produced in the mixing chamber 38 is supplied under air pressure to the bags 20 via a distribution pipe 44, which acts as a secondary mixing chamber. That is to say that while the foam is traveling along the distribution pipe 44, the foaming process continues. The distribution pipe 44 is at least 10 feet long and has a diameter of about 1 inch or greater.

As shown in FIG. 5, each bag 20 has an inlet 46 at a top end thereof for receiving the foam from the distribution pipe 44. A valve 48 is preferably provided at the inlet 46 of each bag 20 for allowing the bags 20 to be individually and separately filled with foam. In this way, bags of a same series can be deployed while others can remain retracted as shown in FIG. 1. Each bag 20 is further provided at a bottom end thereof with an outlet 50 connected to a return line 52 to permit drainage of the liquid resulting from the degradation of the foam in the bags 20. A valve 54 is preferably provided at the outlet 50 of each bag 20 to allow for pressure differentiation between the inlet and the outlet thereof. Once the bags 20 have been filled, the valves 54 remain open to allow for continuous draining of excess fluid from the liquid foam, to be returned to the reservoir via the return line 52. The inlet valves 48 and the outlet valves 54 are controlled individually for each of the bag connections so as to modulate the flow of material in and out.

The selectively openable bag inlets 46 and bag outlets 50 provide for the enlargement of the bags 20 by air pressure or by foam pressure while allowing liquid emanating from the liquid foam during the insulation process or at the end of the foam cycle to be drained off by gravity or by using a vacuum. Either the cables 22 or the bags 20 may be designed at an angle of slope so as to maintain a constant drainage slope towards the bag outlets 50.

FIG. 2 shows the bags 20 in a folded state. The bags 20 are retracted on the sides of the building, thereby allowing light to enter into the building envelope through the roof structure thereof.

FIG. 3 shows the bags 20 in the process of being deployed. At this stage, the bags 20 are only partially filled with liquid foam. The inlet valves of the bags 20 to be deployed are opened and the foam generators 30 are operated to direct a completed foam product at the inlets 46 of the bags 20 via the distribution pipes 44. The bags 20 are gradually filled with the foam, thereby causing the deployment thereof from their storage position shown in FIG. 2. The outlet valves 54 can be periodically opened during the bag filling process to allow air to be pushed out of the bags 20 by the foam and also to permit liquid to drain off the bags 20.

FIG. 4 shows the bags 20 fully expanded to a point where they touch and interact with the corresponding bags 20 coming from the other side. The bags 20 extend along the transversal trusses 16 so as to fill in the bays 18 with a soft attachment of the bag material touching on the aluminum or steel bracing. Once the bag filling process has been completed, the inlet valves 48 are closed.

The bags 20 may be slid by hand, air pressure or foam pressure and returned to their storage position (FIG. 2) folded by mechanical means, hand or vacuum pressure. The emptying operation could, for instance, be achieved by using a typical roller device which can roll up the material and empty it of any contents at the same time.

The bags 20 may have a further attachment to rinse them periodically with a sprinkler (not shown) on the inside of each bag. Also it is noted that sectional bags could be fixed within the roof section of the building and provided with a number of openings for allowing for foam insertion by pressure, exhaust outlets for excess air and separate outlets to vacuum the deteriorating foam back to the reservoir.

The liquid foam filled expandable and collapsible bags are advantageous in that they can form both the roof section and exterior side wall of the building. They can also be installed within roof membranes, glass or plastic, or walls. Moreover, as described hereinbefore, the bags 20 are retractable on demand so that they are completely removed to the greatest extent, i.e. about 98%, from the natural light penetration through the exterior wall or through the open or covered roof.

An additional benefit of the present system is that the bags 20 can be selectively individually expanded to cover selected building sections to be shaded or insulated, at will, on a timed or manual basis. The bags 20 can be made of transparent materials or colored materials for the benefit of certain crops and growing patterns. Varying the thickness of liquid foam insulation is applicable when shading, cooling or insulating. Alternatively, the foam itself could be colored. By varying the density of the coloring of the foam, the foam can have different effects on the plants in the greenhouse.

One further benefit of the system is that by using the dynamic liquid foam, it is possible to chill the insulation inside the expanded bags 20 and create condensation on the lower surface thereof which can then be collected as a method of dehumidification within the building structure. A heat exchanger (not shown) can be coupled to the surfactant reservoir 32 to cool or heat the surfactant solution depending if it is, desired to cool or heat the interior space of the building structure.

In addition of thermally shielding and shading the building, the dynamic liquid foam can also be used as a new method of providing sound insulation. For sound insulation purposes, the foam can be generated and delivered to the wall and roof cavities as per the way described hereinbefore in connection with thermal insulation and shading applications.

According to a further aspect of the present invention, the above-described foam generator 30 is coupled to a series of sprinklers 60 distributed along the distal end portion of the distribution line 44 to spray-apply a fine density fluid insulation foam into the roof or wall cavities 62 defined between the inner and outer layer of the covering membrane 26 (FIGS. 6 to 8) or, alternatively, onto the exterior of the covering membrane 26 of the building structure (FIG. 9).

As shown in FIGS. 6 to 8, the sprinklers 60 can be advantageously positioned in the roof cavities 62 to spray a uniform layer of foam between the layers 26 a and 26 b. The use of the sprinklers 60 is advantageous in that the density of foam is more uniformly distributed in the cavities 62 and it allows varying the density or the thickness of the layer foam that is being applied. FIGS. 6 and 8 show the cavities 62 in the process of being filled with the dynamic insulation foam. In FIG. 7, the filling operation has been completed. The liquid resulting from the degradation of the foam in the cavities 62 is directed by gravity into gutters 64 mounted along the sides of the building at the bottom of the wall cavities 62. It is understood that the gutters 64 could also be mounted at the top of the building structure. A return pipe 66 is provided for allowing the liquid collected into the gutters 64 to be redirected back into the surfactant reservoir 32. The sprinklers could also extend below the truss structure for spray applying a layer of foam on a retractable drape or membrane mounted to trusses 16. The trusses 16 would have sprinklers on the interior of the solar structure spraying on the flat drape that is horizontally stretched between trusses 16, except for a moderate slope to one end on the interior.

According to the embodiment shown in FIG. 9, the sprinklers 60 extend outwardly above the roof structure of the greenhouse 10 for spray-applying a layer of insulation foam on the outer surface of the covering membrane 26. A by-pass could be provided for selectively connecting the distribution line 44 to a washing liquid reservoir 65 (FIG. 7) in order to spray a washing liquid on the covering membrane 26 or between the layers 26 a and 26 b thereof via the sprinklers 60.

The use of such a sprinkler system with a surfactant solution of 1% to 5% surfactant concentration can advantageously be used as a shading system in a given solar structure. The benefit of using this liquid foam, in various degrees of generated foam, is that it enables the operator to shade the sunlight and create a better dispersion of sunrays within the solar structure.

Generation of the liquid foam can be handled by two methods: one using a foam generator, which creates the normal liquid foam, or using a sprinkler system with a surfactant based solution spraying a light foam on the desired surface. This combination will result in a lower level of shading than the standard liquid foam. The result of using the liquid foam, in these various densities and foam placement methods, enables the user to vary the quality of foam and the intensity of shading delivered. In so doing, the operator, in different climates and different sunlight conditions, can reduce the Photosynthetically Active Radiation (PAR) and the direct sunlight effects on the interior space. This will have the following results:

Direct sunlight energy, at peak hours, can be reduced from 1,000 W/m² to approximately 800 w/m², or lower, when required. The coating of liquid foam absorbs and reflects a portion of the infrared waves, thus reducing the solar radiation penetrating the structure.

PAR can be reduced from 1000 nm to 600 nm, or lower, when required. The coating of liquid foam filters a portion of the visible light allowing only the amount of desired light to penetrate.

The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without department from the scope of the invention disclosed. 

1. An insulation/shading system for a building structure, comprising a dynamic fluid foam generator, a plurality of inflatable/deflatable containers adapted to be mounted to the building structure, each of said plurality of inflatable/deflatable containers having an inlet connected to said dynamic fluid foam generator for allowing filling of the containers with a dynamic fluid insulation foam and an outlet for draining the liquid resulting from the degradation of the insulation foam, said inflatable/deflatable containers being movable between an expanded operational position in which the containers are filled with said dynamic fluid insulation foam and a retracted storage position in which the dynamic fluid insulation foam has been substantially emptied from the containers, and wherein the dynamic fluid foam generator is located outside the inflatable/deflatable containers, the foaming process being initiated externally of the inflatable/deflatable containers by the foam generator.
 2. The insulation/shading system as defined in claim 1, wherein at least some of said containers are individually deployable.
 3. The insulation/shading system as defined in claim 1, wherein first and second valves are respectively provided at said inlet and said outlet of at least some of said containers.
 4. The insulation/shading system as defined in claim 1, wherein each of said plurality of containers defines a drainage slope to direct the liquid resulting from the degradation of the insulation foam to the outlet of the container.
 5. The insulation/shading system as defined in claim 1, wherein a source of vacuum is connected to the outlets of the containers to collapse the containers and empty the containers from the content thereof.
 6. The insulation/shading system as defined in claim 1, wherein said containers are retractable along at least one side of the building structure.
 7. The insulation/shading system as defined in claim 1, wherein said containers are slidable along a guiding system spanning the building structure.
 8. The insulation/shading system as defined in claim 1, wherein the containers are mounted via slides to cables stretched across the building structure.
 9. The insulation/shading system as defined in claim 1, wherein said fluid foam generator comprises a reservoir containing a foaming solution, a pump for pumping the foaming solution into a mixing chamber where the foaming solution is mixed with pressurized air, and a secondary mixing chamber along which the foaming process continues before the foam be directed into the containers.
 10. The insulation/shading system as defined in claim 9, wherein an air blower is provided to discharge pressurized air into the mixing chamber as the foaming solution is being injected therein.
 11. A method for periodically insulating/shading a building structure comprising the steps of: a) mounting a plurality of inflatable/deflatable bags to the building structure, b) generating degradable fluid foam outside of said inflatable/deflatable bags, and c) deploying the bags from a retracted state to an expanded state and filling the bags with the pre-formed degradable fluid foam.
 12. The method as defined in claim 11, wherein step b) comprises the step of creating a high density liquid foam by injecting pressurized air in a fluid containing a foaming agent and water.
 13. The method as defined in claim 12, wherein the high density liquid foam is obtained by separately injecting pressurized air and a surfactant in a mixing chamber.
 14. The method as defined in claim 11, comprising the step of using air pressure to carry the fluid foam from a mixing chamber to the bags via a piping network.
 15. The method as defined in claim 11, wherein each bag has a selectively closable inlet, and wherein step c) comprises the steps of: selecting a section of the building to be insulated, and opening the inlets of the bags located in this section.
 16. A system for periodically thermally shielding/shading a building structure with a degradable fluid foam for insulation and shading, the system comprising a foam generator adapted to produce the degradable fluid foam, a distribution pipe connected to an outlet of the foam generator for receiving the foam, and a number of sprinklers connected to the distribution pipe for spray-applying the foam on the building structure interior or exterior.
 17. The system as defined in claim 16, wherein the foam generator comprises a reservoir containing a surfactant solution, a pump for pumping the surfactant solution from the reservoir into a mixing chamber, and an air blower for injecting pressurized air into said mixing chamber while the surfactant solution is being pumped therein in order to produce the degradable fluid foam.
 18. The system as defined in claim 16, further comprising foam containers provided on the building structure for receiving the foam from the sprinklers.
 19. The system as defined in claim 18, wherein said foam containers are provided in the form of wall or roof cavities defined between first and second structural membranes mounted to building structure.
 20. The system as defined in claim 16, wherein said sprinklers extend outwardly of said building structure for spray-applying a layer of foam on the exterior of the building structure.
 21. A system for periodically insulating/shading a transparent building structure, comprising a number of sprinklers spraying liquid foam onto a membrane adapted to be mounted to the building structure, and a foam return line for recuperating the liquid which result from the degradation of the foam over time.
 22. The system as defined in claim 21, wherein the sprinklers are mounted along a distribution line connected to a source of liquid foam.
 23. The system as defined in claim 22, wherein said source of liquid foam comprises a mixing chamber in which pressurized air and a surfactant solution are separately injected.
 24. A system for washing the exterior of a greenhouse, comprising a number of sprinklers distributed along a distribution line connected to a source of washing fluid, the sprinklers extending outwardly of the greenhouse for spray-applying a washing fluid on the exterior of the greenhouse.
 25. A method of producing a sound insulation, comprising the steps of: providing a source of foaming solution consisting essentially of a surfactant and water, providing a source of pressurized air, and mixing the foaming solution with the pressurized air to generate dynamic liquid foam. 